Dietary Supplementation with Methionine and Lysine Enhances Antioxidant Function and Muscle Quality of Hefang Crucian Carp (Carassius auratus)

Moreover, the MA group exhibited superior muscle hardness and gumminess, while the HA group had higher springiness and chewiness (P <0.05). Muscle fiber density was significantly increased, whereas diameter and area showed the opposite trend in fish fed 1.7% Met and 3.4% Lys (P < 0.05). Furthermore, appropriate Met and Lys supplementation significantly affected muscle fiber development genes (MyoD, MyoG, and MRF4), with MyoG highest in the HA group and MyoD and MRF4 highest in the MA group (P < 0.05).

Comparative transcriptomic analysis of muscle tissue showed DEGs functional enrichment primarily correlated with muscle quality, involving cardiac muscle contraction, actin cytoskeleton regulation, PPAR signaling pathway and ECM-receptor interaction. Taken together, our findings enhance the understanding of the molecular mechanisms underlying the effects of dietary Met and Lys on muscle quality in HCC, providing valuable insights for the development of nutritional strategies in the aquaculture industry.